In any construction procedure, soil erosion is usually a major problem. With soil erosion, prevention is always easier than correction. Many ways are known in the prevention of soil erosion. In soil areas, with vegetation growing, the root system of the plants can prevent erosion. So, the faster root growth can occur in the area, the more likely it is that soil erosion can be prevented, or at least minimized.
Current erosion treatments are carried out after the site is graded and seed is applied. A site-specific seed type and cover crop are applied by broadcast seeding, slip seeding, drill seeding, or hydro-seeding. With favorable weather conditions or supplemental watering in controlled increments, the seed source may start to establish within three or four weeks. The soil can then be stabilized with the living plants. In the meantime, this practice presents a great potential problem for causing soil loss by erosion, due to the period of no vegetation and lack of emerging root growth.
Typical seeds for cover crops include, but are not limited to annual rye, fescue and spring oats. Seeding generally takes longer to establish the root system to minimize or prevent erosion. Those plants usually require two or three growing seasons for maturity and the establishment of good ground cover. In normal practices, job site and outside conditions affect the success of seed growth. Heavy rain or hot climates can cause the seed or soil to erode without proper maintenance.
In extremely difficult climates, additional water and herbicide treatments are necessary to establish the seed and create a root base to minimize erosion. If the site is already suffering from damage, such as erosion problems, additional soil and seed applications may be necessary. Such actions add greatly to the expense of erosion prevention.
Soil customarily contains tremendous amounts of seed sources that produce weeds. Once the soil is disturbed, new annual weeds will begin to germinate, and overtake a cover crop and the native seed source. Weeds are very undesirable. Avoidance of a weed crop is very desirable. Quick growth of desired vegetation is a very desirable method of avoiding a weed crop.
Currently, live plugs, which are small pieces of desired vegetation, are the only way to produce immediate vegetation coverage to compete with weed seeds. Planting the live plugs is labor-intensive. The plugs themselves are also costly. Then, the maintenance of the plugs is a problem.
Additionally, because of short growing seasons in the upper Midwest, the success of the native species and its growth will be shortened. It will therefore take more growing seasons to have any native species function as the erosion-preventing ground cover. In that case, treatments to prevent extreme weed competition can include controlled burns or herbicides. Such treatments can cause more problems than they solve. A controlled burn requires a fire department presence for reasonable safety. Herbicides have environmental consequences, even with careful application thereof.
Normally when exposed soil is to be seeded after the grade, a seed type is applied by either broadcast or hydro-seeding. But at application, the specified seed is just that, seed. It has not developed into an erosion preventing plant. Thus, it usually will take a three to four week period, under good growing conditions, to produce a cover crop. Seed generally takes longer to establish than living plants to take hold and root.
Also, a seeding process is usually fighting many uphill battles. Inclement weather types, such as heavy rains, extreme heat or both, may prevent seeds from rooting or sprouting. Even under an erosion control blanket, seeds still have those problems. If the construction site is already wet or has a fast and unpredicted rise of water flow, because of urban run off or naturally occurring stream rising or falling, it creates additional issues for seeds. Other problems for seeds include spikes in runoff or rain fall which can prevent full establishment of the seed.
If the seeding processes needs to be repeated, much more labor, expense, and tremendous efforts are required to repeat ground preparation and to re-seed. In contrast, if the initial seeding process is successful, the originally installed seeds require constant maintenance; such as adding new soil, reseeding, using additional water or re-blanketing as a special erosion control measure. These ongoing maintenance operations add a tremendous additional expense. If the project is successful for normal operation standards, weed treatments such as herbicides or cutting still must be done to allow access for Native foliage to grow. Then, in most of the United States, the summer heat arrives for many weeks. Native foliage, being succulent and young cannot fight the annual weed competition.
Such plantings are not acceptable and will not get the appropriate signing off as successful by the permitting authority, engineers or the contractor. General contractors and subcontractors are not paid until the project is approved, thereby restricting cash flow.
While this may seem odd, under normal practices, this is usually how commercial jobs operate. Because of unit costs up front, ground cover installation prices per unit are very expensive. No appropriate solution is currently available.
The true price per unit is high and still may take years to see true success. In the interim, soil loss and natural waterways, wetlands, or other areas are polluted. Remedies therefore occur at a large cost. Compounding daily across the United States is a large scale environmental problem from non source point pollution.
It is very necessary to create an alternative process to limit loss exposure and create situations to have a better chance of success; such success including, but not limited to, reduced overall herbicide use and limiting the damage of storm events, thereby allowing credible changes in plant community establishment faster and protecting our environment. To that end, it is very desirable to have an efficient method of getting desired vegetation in a desired place quickly. It is furthermore valuable to be able to control erosion and produce native grass or turf grass on difficult sites or erodible soils quickly and efficiently with reduced labor and maintenance requirements.
Attempts to solve some of these problems with vegetated blankets can also be a problem. It is difficult to produce a proper blanket for control of erosion. Additionally, it is difficult to move the blankets to a desired location. Then application of the blanket to the desired surface can be complicated and difficult.
Traditionally, landscape blankets are rolled and transported to an installation site via trucks. Rolled or block cut sod is rolled and transported via truck after cutting established root growth. Further, in the transportation process, roots are compressed and further damaged.
It will be a useful invention to create a tray which allows a prevegetated blanket to form and grow in the tray. Then, the tray can be transported to the job site via truck without rolling the prevegetated blanket or cutting or damaging established root growth.